{"product_id":"xiaomi-redmi-6a-replacement-battery-385v-2900mah-li-polymer","title":"Xiaomi Redmi 6A Replacement Battery BN37 3.85V 2900mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eXiaomi Redmi 6A — 3.85V Li-Polymer Replacement Battery (BN37)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThe BN37 is a 3.85V, 2900mAh Li-Polymer cell that fits the Xiaomi Redmi 6A and Redmi 6A Dual SIM TD-LTE, including variants M1804C3DH and M1804C3DC. It replaces a degraded original cell when the phone no longer holds a charge or shuts down unexpectedly under load. Capacity matches the factory specification at 11.17Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eRedmi 6A platform fit:\u003c\/strong\u003e\n    The M1804C3 hardware family shares a single battery bay, connector pinout, and BMS handshake across all Redmi 6A variants. The BN37 slot and NTC thermistor pin position are consistent across these builds, so one cell covers the full model range listed.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell on a Redmi 6A unit and confirmed the BMS accepted charge at both standard and fast-charge rates. The protection circuit tripped correctly at low-voltage cutoff, and charge termination occurred cleanly at full capacity.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installation, disable fast charging and run one full discharge-charge cycle at the standard rate. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated measurement window.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Redmi 6A reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Redmi 6A uses a coulomb-counter fuel gauge IC that stores a discharge curve calibrated to the original cell. When a new cell goes in, the stored curve no longer matches the actual voltage-versus-capacity profile of the replacement. The gauge reads the new cell's voltage and maps it against old data, producing percentage figures that jump or plateau. One complete slow discharge from 100% to shutdown — followed by a full charge — resets the calibration baseline and the percentage display stabilises.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC has not yet recalibrated and the cell voltage drops below the modem or display load threshold faster than the displayed percentage predicts. The phone's BMS issues a hard cutoff to protect the cell, even though the screen shows charge remaining. It is not a faulty battery — it is a calibration mismatch. Complete one full discharge-charge cycle at standard rate; after recalibration, the cutoff should align with a displayed level below 5%.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392024543322,"sku":"BWCS-MUR610SL-1","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392024576090,"sku":"BWCS-MUR610SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392024608858,"sku":"BWCS-MUR610SL-3","price":30.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MUR610SL-1.webp?v=1779142944","url":"https:\/\/batteryweb.com\/products\/xiaomi-redmi-6a-replacement-battery-385v-2900mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}